Postoperative external tibial rotation is correlated with inferior meniscal healing following pullout repair of a medial meniscus posterior root tear

Purpose: The purpose of this study was to evaluate the influence of tibial rotation on the postoperative healing status of the medial meniscus (MM) following pullout repair of MM posterior root tear (MMPRT).

Methods: Ninety-one patients (68 women and 23 men, mean age: 63.3 ± 8.8 years) who had undergone transtibial pullout repair of MMPRT were enrolled in the study. The tibial external rotation angle (ERA) in each patient was measured postoperatively using computed tomography in the extended knee position. The meniscal healing status following transtibial pullout repair was assessed by second-look arthroscopy (mean postoperative period: 12 months) using a previously published scoring system (range 0–10). The association between ERA and meniscal healing score was investigated using univariate linear regression models. The ERA cut-off for improved meniscal healing score (≥ 7) was determined using receiver-operating characteristic analysis.

Results: The ERA and meniscal healing score were significantly associated, this confirming increased ERAs to be correlated with worse meniscal healing status (R = -0.28; P < 0.001). The optimum ERA cut-off was 0.69º, with a sensitivity of 65% and a specificity of 66%. The mean meniscal healing score was 7.2 among patients with an ERA of < 0.69º, and 6.1 among patients with an ERA of ≥ 0.69º (P < 0.001).

Conclusion: This study demonstrated that ERA was significantly correlated with postoperative meniscal healing status. Postoperative tibial rotation could be one of the causes affecting postoperative outcomes of pullout repair of MMPRT. Surgeons should consider some protective strategies for the repaired meniscus in patients with large postoperative tibial external rotation.

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00167-021-06656-y